It seems beyond doubt that the tariff policy pursued during the last half century has not raised the standard of living of the labouring classes. It is doubtful if agricultural duties increase the relative scarcity of manual labour compared with other factors, and they certainly raise the cost of living for the working classes. It is, however, true that manufacturing duties tend to depress the rent of farm land... It is on the whole not at all unlikely that the sum total of rent is reduced in countries with high manufacturing duties... In most countries, however, the sum of rents is small compared with the sum of wages to manual workers. Even a substantial reduction of the former brings only a slight increase in the latter.